Meeting of Supreme War Council in August 1921; on the front, left to right: British Foreign secretary Lord Curzon, British Prime minister Lloyd George, French Prime minister Briand, Italian Prime minister Bonomi, Italian Minister of Foreign affairs Della Torretta, American ambassador to UK Harvey, Japanese ambassador to UK baron Hayashi, Japanese ambassador to France viscount Ishii; on the second row, left to right: interpreter Camerlynck, British Cabinet secretary Hankey, French Secretary to Ministry of Foreign Affairs Berthelot, French Minister of Liberated regions Loucheur

The Supreme War Council was a central command based in Versailles that coordinated the military strategy of the principal Allies of World War I: Britain, France, Italy, the US and Japan.[1] It was founded in 1917 after the Russian revolution and with Russia's withdrawal imminent.[2] The council served as a forum for preliminary discussions of potential armistice terms as well as peace treaty settlement conditions, and it was succeeded by the Conference of Ambassadors.

Following the Italian defeat at the Battle of Caporetto, in which the Germans and Austro-Hungarians surprised the Italian forces, Lloyd George proposed the formation of the Supreme War Council at the Rapallo Conference of 5–7 November 1917.

Japan and Russia were not to be included, and the Italians and French, worried that Salonika might be evacuated, wanted it confined to the Western Front.[3]

The USA, which was "Associated" with the Allies, was not involved with the political structures, but sent a Permanent Military Representative, Tasker H. Bliss.[4]

Wilson and his staff conducted numerous research projects into offensives against Turkey, culminating in the "Joint Note 12".[5]

At the Supreme War Council (30 January – 1 February) Hankey recorded that the national Commanders-in-Chief, national Chiefs of Staff and PMRs "all gave different advice" creating "a worse state of chaos than I have ever known in all my wide experience". Lloyd George, whose main goal was to thwart Robertson, blocked a suggestion by Foch (French Chief of Staff) that the proposed Allied Reserve be controlled by the national Chiefs of Staff, possibly prompted by the notes Wilson was passing him across the table. It was eventually agreed that Foch should command the Reserve, with Wilson as his deputy.[6]

The Allied Reserve eventually slipped from the agenda as the Commanders-in-Chief, Haig and Pétain refused to hand over sufficient troops. Early in 1918 Wilson replaced Robertson as CIGS and at the end of March Foch became Allied Generalissimo. After April 1918 all Allied troops on the Western Front were placed under the command of the Grand Quartier général des armées alliées [fr] (GQGA), a multi-national general staff that developed from the Supreme War Council. The GQGA was on similar lines to the GQG and came under General Ferdinand Foch, who had overall command of all Allied troops.[7] Without its two main personalities the military machinery at Versailles became less important.